Dimethylformamide → 6-Bromo-3-pyridinecarboxaldehyde

To a suspension of 2,5-dibromopyridine (18.6 g, 78.5 mmol) in dry diethyl ether (400 mL) at −78° C. was added n-butyllithium (2.5 M in hexanes, 31.4 mL, 78.5 mmol) over a period of 20 min. After stirring 30 min at this temperature, anhydrous DMF (9.1 mL, 118 mmol) was added over a period of 5 min, and the reaction mixture was stirred for 30 min then warmed to room temperature. Saturated NH4Cl (10 mL) was added to the reaction mixture. The layers were separated, and the organic layer was dried (Na2SO4), concentrated. The crude product was purified by column chromatography (1:5 ethyl acetate/hexanes) to afford a brown solid (12.5 g, 86%); 1H NMR (300 MHz, CDCl3) δ 7.61 (dd, J=8.10, 0.60 Hz, 1 H), 7.95 (dd, J=8.10, 2.10 Hz, 1 H), 8.74 (dd, J=2.10, 0.60 Hz, 1 H), 10.02 (s, 1 H); 13C NMR (75 MHz, CDCl3) 129.2, 130.8, 137.7, 148.4, 152.6, 189.7.

1. additionwas added over a period of 5 min
2. customThe layers were separated
3. dry with materialthe organic layer was dried (Na2SO4)
4. concentrationconcentrated
5. customThe crude product was purified by column chromatography (1:5 ethyl acetate/hexanes)

ORD record

ord-afee20ece707411293bbfd5a5f7dd86f

Source dataset

uspto-grants-2002_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06416861B1